Comparison of cardiovascular, hyperthermic, and toxic effects of para-methoxyamphetamine (PMA) and 3, 4-methylenedioxyamphetamine (MDA).

Para-methoxyamphetamine (PMA) and 3, 4-methylenedioxyamphetamine (MDA) both had potent stimulatory effects on mean arterial blood pressure and heart rate in the cat. These effects were antagonized by bretylium, a compound which blocks release of norepinephrine. The increases in heart rate were also antagonized by propranolol and the blood pressure increases by phenoxybenzamine. PMA and MDA were nearly equipotent. In male albino mice, determination of 6 hr LD50's indicated PMA to be most toxic although 24 hr LD50's showed nearly equal toxicity. MDA had a potent hyperthermic effect in mice which was partially antagonized by bretylium and was blocked by haloperidol. The hyperthermic effect of PMA was not as pronounced and was followed by hypothermia.